X-ray fluorescence (XRF) spectroscopy systems and methods are provided. One system includes a source of x-ray radiation and an excitation optic disposed between the x-ray radiation source and the sample for collecting x-ray radiation from the source and focusing the x-ray radiation to a focal point on the sample to incite at least one analyte in the sample to fluoresce. The system further includes an x-ray fluorescence detector and a collection optic comprising a doubly curved diffracting optic disposed between the sample and the x-ray fluorescence detector for collecting x-ray fluorescence from the focal point on the sample and focusing the fluorescent x-rays towards the x-ray fluorescence detector.
|
1. An x-ray fluorescence (XRF) spectroscopy system comprising:
at least one source of x-ray radiation;
at least one x-ray detector;
at least one monochromating collection optic comprising at least one doubly curved diffracting optic disposed between a sample and the at least one x-ray detector for collecting x-ray fluorescence from a focal point on the sample and directing the fluorescent x-rays of a characteristic energy of a predetermined analyte towards the at least one x-ray detector; and
at least one excitation optic disposed between the at least one x-ray radiation source and the sample for collecting x-ray radiation from the at least one source and focusing the x-ray radiation to the focal point on the sample to incite said analyte in the sample to fluoresce.
34. An (XRF) spectroscopy method comprising:
providing at least one source of x-ray radiation;
providing at least one x-ray detector;
disposing at least one monochromating collection optic, comprising at least one doubly curved diffracting optic, between the sample and the at least one x-ray detector for collecting x-ray fluorescence from the focal point on the sample and directing the fluorescent x-rays of a characteristic energy of a predetermined analyte towards the at least one x-ray detector; and
providing at least one excitation optic disposed between the at least one x-ray radiation source and a sample to be analyzed for collecting x-ray radiation from the at least one source and focusing the x-ray radiation to the focal point on the sample to incite said analyte in the sample to fluoresce.
2. The XRF spectroscopy system of
3. The XRF spectroscopy system of
4. The XRF spectroscopy system of
5. The XRF spectroscopy system of
6. The XRF spectroscopy system of
7. The XRF spectroscopy system of
8. The XRF spectroscopy system of
9. The XRF spectroscopy of
10. The XRF spectroscopy of
13. The XRF spectroscopy system of
14. The XRF spectroscopy system of
15. The XRF spectroscopy system of
16. The XRF spectroscopy system of
17. The XRF spectroscopy system of
18. The XRF spectroscopy system of
19. The XRF spectroscopy system of
20. The XRF spectroscopy system of
21. The XRF spectroscopy system of
22. The XRF spectroscopy system of
23. The XRF spectroscopy system of
24. The XRF spectroscopy system of
25. The XRF spectroscopy system of
26. The XRF spectroscopy system of
27. The XRF spectroscopy system of
28. The XRF spectroscopy system of
29. The XRF spectroscopy system of
30. The XRF spectroscopy system of
31. The XRF spectroscopy system of
32. The XRF spectroscopy system of
33. The XRF spectroscopy system of
35. The XRF spectroscopy method of
36. The XRF spectroscopy method of
37. The XRF spectroscopy method of
38. The XRF spectroscopy method of
39. The XRF spectroscopy method of
40. The XRF spectroscopy method of
41. The XRF spectroscopy method of
44. The XRF spectroscopy method of
45. The XRF spectroscopy method of
46. The XRF spectroscopy method of
47. The XRF spectroscopy method of
48. The XRF spectroscopy method of
49. The XRF spectroscopy method of
50. The XRF spectroscopy method of
51. The XRF spectroscopy method of
52. The XRF spectroscopy method of
53. The XRF spectroscopy method of
54. The XRF spectroscopy method of
55. The XRF spectroscopy method of
56. The XRF spectroscopy method of
57. The XRF spectroscopy method of
|
|||||||||||||||||||||||||||||
This application is a continuation of PCT application PCT/US02/19272 filed Jun. 18, 2002, and published under PCT Article 21(2) in English as WO 02/103710 A2 on Dec. 27, 2002. PCT/US02/19272 claimed the priority of U.S. provisional application 60/299,371, filed Jun. 19, 2001. The entire disclosures of both are incorporated herein by reference. This application also contains subject matter which relates to the subject matter of the following commonly-owned patents and applications, each of which is hereby incorporated herein by reference in its entirety:
The field of the present invention relates to x-ray fluorescence (XRF) spectroscopy systems, and in particular, to a system and method which include focusing x-ray optical elements for forming a focusing excitation beam on samples and monochromators for collecting secondary x-rays from the sample.
X-ray fluorescence (XRF) spectroscopy is widely recognized as a very accurate method of determining the atomic composition of a material, achieved by irradiating a sample with x-rays and observing the resulting secondary x-rays emitted by the sample.
In general, XRF systems consist of a source of excitation radiation (an x-ray tube or a radioisotope), a means to detect secondary x-rays from the sample and determine their energy or wavelength, and a display of the spectral output. The intensity of the secondary x-rays at certain energies or wavelengths is correlated to the elemental concentration in the sample. Computer software is often used to analyze the data and determine the concentration.
The process begins by irradiating the sample using a source of x-rays. As x-ray photons strike the sample, they knock electrons out of the inner shell of the atoms that make up the sample, creating vacancies that destabilize the atoms. The atoms stabilize when electrons from the outer shell are transferred to the inner shells, and in the process give off characteristic x-ray photons whose energy is the difference between the two binding energies of the corresponding shells. There are two conventional approaches to determining the x-ray spectrum emitted from the sample. The first approach is energy dispersive spectrometry (EDS), and the second is wavelength dispersive spectrometry (WDS). In an energy dispersive spectrometry system, an energy dispersive detector, such as a solid-state detector or a proportional counter, is used to determine the energy spectrum of the emitted photons from the sample. In a wavelength spectrometry system, a crystal or a multi-layer structure is used to select a specific x-ray wavelength from the x-rays photons emitted from the sample.
X-ray fluorescence using EDS is the most widely used method of elemental concentration analysis. This method has some advantages. First, the EDS detector can detect almost all of the elements in the periodic table at once. Second, the system is compact because an additional optic is not required on the collection side compared to wavelength dispersive x-ray fluorescent systems. Third, a low-power x-ray tube may be used because the EDS detector has a large collection solid angle and high efficiency. There are disadvantages to XRF/EDS systems, however, including relatively poor sensitivity and poor energy resolution. Also, because the EDS detector sees all of the x-rays from the sample, the detector is easily saturated by the fluorescent signal from the major elements and the strong scattering of the primary beam.
X-ray fluorescence using WDS has several advantages also, including higher energy resolution and higher signal-to-background ratio compared with XRF/EDS systems. Thus, the XRF/WDS approach is a powerful tool for trace element analysis and applications that require high energy resolution. However, there are disadvantages to conventional XRF/WDS systems, including a requirement for a high power x-ray tube due to limitations of the WDS approach that result in a low efficiency, and a small collection solid angle. Another disadvantage of a conventional WDS system is that the crystal or multi-layer structure on the collection side only selects a specific x-ray wavelength and a scanning mechanism or multi-crystal system is needed for multi-element detection. This has the advantage that detector saturation may be avoided, but it results in a complicated alignment. Therefore, XRF/WDS systems are typically bulky, complex, and more expensive as compared to XRF/EDS systems.
U.S. Pat. No. 5,982,847 to Nelson discloses an energy dispersive (EDS) system, using only polychromatic optics in both the detection and collection paths. No mention is made of diffracting optics in either the excitation or collection paths.
WO02/25258 to X-Ray Optical Systems, Inc. is also strictly an EDS system. Even though monochromatic excitation is used—the detection path is not limited to specific wavelengths with a detection optic—there is no detection optic disclosed or taught by this document. Therefore, the detection system encounters a broader band of wavelengths and processes this broader band using conventional EDS techniques.
EP 0339713 to N. V. Philips discloses a WDS system, however as discussed above, this document discloses the conventional technique of illuminating a very large sample area, a pinhole/slit 6 to define the angle of incidence upon optic 22, thus severely limiting the collection solid angle. There is no disclosure, teaching or suggestion of a focusing optic, providing a small sample spot size, and the attendant advantages of the present invention. The small sample spot size of the present invention is “placed” at position 6, but without limiting the collection solid angle of the detection optic.
Chen, et al, “Microprobe X-Ray Fluorescence with the Use of Point-Focusing Diffractors,” Appl. Phys Lett. 71 (13) 1884-1886, September 1997 is similar to WO02/25258, discussed above. Even though monochromatic excitation is used—the detection path is not limited to specific wavelengths with a detection optic—there is no detection optic disclosed or taught by this document.
U.S. Pat. No. 5,406,609 to Arai et al. is also similar to WO02/25258 —monochromatic excitation with a standard EDS detection scheme.
While most XRF instruments are generally for the analysis of a wide range of elements, there are many important applications in industry process control that require single element or limited element detection. Thus, the present invention is directed to providing compact XRF/WDS systems that provide an ultra high sensitivity or high speed analysis for a limited number of elements.
The shortcomings of the prior approaches are overcome, and additional advantages are provided, by the present invention which in one aspect comprises an x-ray fluorescence (XRF) spectroscopy system. The XRF system includes at least one source of x-ray radiation and at least one excitation optic disposed between the at least one x-ray radiation source and the sample. The at least one excitation optic collects x-ray radiation from the at least one source and focuses the x-ray radiation to a focal point on the sample to incite at least one analyte in the sample to fluoresce. The system further includes at least one x-ray detector and at least one collection optic. The at least one collection optic comprises at least one doubly curved diffracting optic disposed between the sample and the at least one x-ray detector for collecting x-ray fluorescence from the focal point on the sample and directing the fluorescent x-rays towards the at least one x-ray detector.
Numerous enhancements on the above-described XRF spectroscopy system are also described and claimed herein. For example, the at least one source of x-ray radiation could comprise at least one electron bombardment x-ray source. The at least one excitation optic could comprise at least one focusing polychromatic optic, for example, one or more polycapillary optics, and/or could comprise at least one focusing monochromatic optic. The focusing monochromatic optic(s) could comprise at least one doubly curved crystal and/or at least one doubly curved multi-layer optic. The focal point could have a focal spot size of less than 500 microns, and the sample could be a solid or a fluid. Further the sample could be a petroleum based product, such as gasoline, diesel, crude oil or lubrication oil. The at least one analyte to be incited within the sample could comprise sulfur and/or iron. In addition, the x-ray radiation focused on the sample may be incident on the sample at an angle less than the angle of total external reflection, as desirable for total reflection x-ray fluorescence (TXRF), or the x-ray radiation focused on the sample may be incident on the sample at an angle greater than the angle of total external reflection, as desirable for normal x-ray fluorescence.
Further enhancements may include the at least one collection optic directing x-rays of the at least one analyte towards the detector(s) for determining concentration of the at least one analyte in the sample or a thickness of the sample. Further, the at least one doubly curved diffracting optic of the at least one collection optic could comprise at least one doubly curved crystal. The at least one doubly curved crystal could have a Johann geometry, a Johannson geometry, a partial Johannson geometry approximation, or could comprise a logarithmic spiral crystal optic. Still further, the at least one doubly curved diffracting optic could comprise at least one doubly curved multi-layer optic, which could be a doubly curved graded optic, or a doubly curved logarithmic spiral optic in certain embodiments. Still further, the at least one collection optic could be fixed relative to the sample and the at least one x-ray detector. The at least one x-ray detector could be one or more gas proportional counters, one or more scintillation counters, and/or one or more solid state detectors. The one or more solid state detectors could comprise at least one PIN diode solid state detector.
In another aspect, an x-ray fluorescence spectroscopy (XRF) method is disclosed. This method includes: providing at least one source of x-ray radiation; providing at least one excitation optic disposed between the at least one x-ray radiation source and a sample to be analyzed for collecting x-ray radiation from the at least one source and focusing the x-ray radiation to a focal point on the sample to incite at least one analyte in the sample to fluoresce; providing at least one x-ray detector; and disposing at least one collection optic, comprising at least one doubly curved diffracting optic, between the sample and the at least one x-ray detector for collecting x-ray fluorescence from the focal point on the sample and focusing the fluorescent x-rays towards the at least one x-ray detector.
Additional features and advantages are realized through the techniques of the present invention. Other embodiments and aspects of the invention are described in detail herein and are considered a part of the claimed invention.
The subject matter which is regarded as the invention is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other objects, features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:
Generally stated, one embodiment of a compact XRF/WDS system in accordance with an aspect of the present invention comprises an x-ray source, an excitation x-ray optic that focuses x-rays onto a sample from the source, at least one collection monochromator and an x-ray counter. The excitation x-ray optic can be a focusing polycapillary optic that provides polychromatic excitation or a point-focusing doubly curved crystal optic that provides monochromatic excitation. The collection monochromator (which can be a doubly curved crystal optic, a doubly curved multi-layer optic, or other doubly curved diffracting optic) selects a desired characteristic wavelength of an element. The intensity of the reflected x-rays is measured by a detector and is correlated to the concentration of this element in the specimen.
One aspect of an XRF/WDS system in accordance with the present invention is that the excitation optic can efficiently capture a large cone angle of x-rays from a point x-ray source. This optic is a focusing optic which can produce a very intensive excitation beam on the sample even with the use of a compact, low-power (e.g., <1 KW, and more beneficially <100 W) x-ray source. The use of a low-power x-ray tube makes this system much more compact and simpler compared with a conventional XRF/WDS system using a bulky kw x-ray tube.
Another aspect of this invention is that a monochromatic excitation beam can be produced if a doubly curved crystal optic is used as the excitation optic. In a typical embodiment of an XRF/WDS system, a polychromatic beam is used to excite the sample. Monochromatic excitation gives much higher signal-to-background ratio than polychromatic excitation due to the elimination of the scattering bremsstrahlung from the x-ray source on the sample. This improves the detection limit of the system significantly. Monochromatic excitation also greatly simplifies the quantitative analysis of XRF.
Still another aspect of this invention is that the excitation beam is focused on the sample because of the focusing capability of the excitation optic. The focal spot size of the beam on the sample may be in the range of 50μ to 500μ, which is about two orders of magnitude smaller that the beam size of a conventional system (which is typically ˜10 mm-30 mm). Besides providing efficient collection, this smaller beam size allows spatial resolution in the analysis.
Due to the smaller sample excitation area, a doubly curved diffracting optic can be efficiently used as the collection optic (in another aspect of the present invention). Doubly curved monochromatic optics can provide large collection solid angles from a spot. (In a conventional XRF/WDS system with a large excitation beam size, a flat or singly curved monochromator is the choice and the collection solid angle is limited.) A doubly curved monochromator improves the signal level considerably for the detected element for a given geometry and intensity of the excitation beam.
A further aspect of this invention is that the collection optic can be fixed relative to the sample and the detector, with no moving parts involved. This could have both advantage and disadvantage. An advantage would be that it speeds up the analysis and improves system reliability, while a disadvantage is that multiple collection optics may be necessary; for example, for multi-element analysis.
To restate, in accordance with the principles of the present invention, an XRF/WDS system is described with x-ray focusing optics providing polychromatic or monochromatic excitation to a sample. Secondary x-rays that result from x-ray fluorescence are collected by a monochromator, which comprises a doubly curved diffractor, for forwarding to a detector such as a proportional counter, a room temperature PIN detector, or a NaI detector. One example of an XRF/WDS system 100 using such x-ray optics to provide monochromatic excitation and collect x-rays from the sample is described in detail below with reference to FIG. 1.
XRF/WDS system 100 includes, for example, a low power x-ray source 110, a monochromatic focusing optic 120, a sample 130, a collection monochromator 140, and a detector 150.
Low power x-ray source 110 (e.g., <1 KW, and more ideally <100 W) is a source of x-ray radiation such as an x-ray tube, a sealed source of radioactive material, or a source of high energy electrons that impinge upon a metal target and produce x-ray radiation. One example of low power x-ray source 110 is a 50 W x-ray tube, with a target material comprising chrome, copper, tungsten, or molybdenum, and an electron beam size on the target material in the range of approximately 50 μm to 300 μm.
Sample 130 is a material to undergo metrology measurements . An example of sample 130 may be a process flow such as diesel fuel from which measurement of the concentration of sulfur is desired, or lubricating oil from which measurement of the concentration of wear metal (iron) is desired. If sample 130 is a fluid flow, a window material (not shown) may be included to enable transmission of x-ray excitation radiation into and x-ray fluorescence out of sample 130.
Monochromatic focusing optic 120, located between x-ray source 110 and sample 130 of XRF system 100, serves to reflect or transmit only radiation within a small range of energies to sample 130, e.g. within a range of energies between tens or hundreds of electron-Volts, as opposed to polychromatic optics, which transmit radiation with energy bandwidths in the thousands of electron-Volts. Optic 120 also focuses the x-rays to a small focal spot on sample 130. The size of this focal spot may be in the range of 50 μm to 500 μm.
One example of focusing optic 120 is a Johann type doubly curved crystal. An example of the geometry of a Johann type doubly curved crystal is shown in FIG. 2. In this geometry, the diffracting planes of the crystal 160 are shown parallel to the crystal surface. The crystal surface, which is a toroidal shape, has the Johann geometry in the plane of the focal circle 170 and axial symmetry along line SI, where point S is the location of the x-ray source 110 (
As shown in
A specific example of a collection monochromatic optic 140 is a doubly curved logarithmic spiral crystal optic. One embodiment of this geometry is illustrated in
Alternately, multilayer optics may be employed in the system of
Advantageously, XRF/WDS system 100 is well suited for high-sensitivity trace elemental analysis. The point-to-point focusing doubly curved crystal optic provides a large collection solid angle and forms a very intense focusing monochromatic beam on the sample even with the use of a low power x-ray tube. Due to the monochromatic excitation, the signal-to-background ratio is improved significantly and the detection sensitivity is improved. Point focusing of the excitation beam onto the sample enables the efficient use of a doubly curved collection optic to improve the collection solid angle of the fluorescence x-rays. This will further improve sensitivity of the system.
As one specific embodiment of XRF/WDS system 100 of
By adding one or more collection monochromators and detectors to system 100, two or more elements can be detected, with each collection monochromator paired to a detector for a respective, single element detection.
Polychromatic optic 220 is an optical element which transmits a broad range of photon energies, while focusing the photons it collects to a small spot on sample 230. One example of a polychromatic optic that is well suited to function as optic 220 is a polycapillary optic 300 (see FIG. 5), such as available from X-Ray Optical Systems, of Albany, N.Y. A polycapillary optic, which is described in detail in many of the above-incorporated patents, is a bundle of thin, hollow tubes that transmit photons via total reflection.
Due to the polychromatic excitation, the signal-to-background ratio will be poorer than compared to that of system 100 (FIG. 1). However, system 200 (
In one specific embodiment, XRF/WDS system 200 may include an x-ray source 210 which may be a 50 W x-ray tube with a source material of chrome, copper, tungsten or molybdenum and a spot size on the target material that is approximately 100 μm to 300 μm. The polychromatic optic 220 may be a polycapillary optic located 30 mm to 50 mm from x-ray source 210. The sample 230 may be, for example, oil with elements that may include sulfur, vanadium, and nickel. The sample 230 could be located 100 mm to 200 mm from polycapillary optic 220. Doubly curved monochromator 240 may be a doubly curved log spiral crystal that is fabricated from silicon, germanium, or other crystal material and is located 100 mm to 200 mm from the sample 230 measured along the optical axis. Detector 250 could be is a gas proportional counter, a scintillation counter, a room temperature PIN detector, or a NaI detector located 100 mm to 200 mm from the monochromatic optic 240 measured along the optical axis. Multiple collection monochromators with corresponding detectors could also be used for multi-element detection.
Although preferred embodiments have been depicted and described herein, it will be apparent to those skilled in the relevant art that various modifications, additions, substitutions and the like can be made without departing from the spirit of the invention as defined in the following claims.
| Patent | Priority | Assignee | Title |
| 10175185, | Mar 26 2015 | Rigaku Corporation | Methods for manufacturing doubly bent X-ray focusing device, doubly bent X-ray focusing device assembly, doubly bent X-ray spectroscopic device and doubly bent X-ray spectroscopic device assembly |
| 10302579, | Dec 25 2014 | Rigaku Corporation | Grazing incidence x-ray fluorescence spectrometer and grazing incidence x-ray fluorescence analyzing method |
| 10677744, | Jun 03 2016 | U.S. Department of Energy | Multi-cone x-ray imaging Bragg crystal spectrometer |
| 10845491, | Jun 04 2018 | SIGRAY, INC | Energy-resolving x-ray detection system |
| 10962491, | Sep 04 2018 | SIGRAY, INC | System and method for x-ray fluorescence with filtering |
| 10976273, | Sep 19 2013 | Sigray, Inc. | X-ray spectrometer system |
| 10989822, | Jun 04 2018 | SIGRAY, INC | Wavelength dispersive x-ray spectrometer |
| 10991538, | Jul 26 2018 | Sigray, Inc. | High brightness x-ray reflection source |
| 11054375, | Sep 15 2016 | University of Washington | X-ray spectrometer and methods for use |
| 11056308, | Sep 07 2018 | SIGRAY, INC | System and method for depth-selectable x-ray analysis |
| 11143605, | Sep 03 2019 | SIGRAY, INC | System and method for computed laminography x-ray fluorescence imaging |
| 11175243, | Feb 06 2020 | SIGRAY, INC | X-ray dark-field in-line inspection for semiconductor samples |
| 11215572, | May 18 2020 | SIGRAY, INC | System and method for x-ray absorption spectroscopy using a crystal analyzer and a plurality of detector elements |
| 11217357, | Feb 10 2020 | SIGRAY, INC | X-ray mirror optics with multiple hyperboloidal/hyperbolic surface profiles |
| 11428651, | May 18 2020 | Sigray, Inc. | System and method for x-ray absorption spectroscopy using a crystal analyzer and a plurality of detector elements |
| 11549895, | Sep 17 2020 | SIGRAY, INC | System and method using x-rays for depth-resolving metrology and analysis |
| 11686692, | Dec 07 2020 | SIGRAY, INC | High throughput 3D x-ray imaging system using a transmission x-ray source |
| 11733185, | Jul 04 2018 | Rigaku Corporation | Fluorescent X-ray analysis apparatus comprising a plurality of X-ray detectors and an X-ray irradiation unit including a multi-wavelength mirror |
| 11740190, | May 27 2020 | Shimadzu Corporation | X-ray analysis device including a spectrometer to detect characteristic X-rays and related X-ray analysis method |
| 11796490, | Sep 15 2016 | University of Washington | X-ray spectrometer and methods for use |
| 11815480, | Apr 20 2018 | Metso Minerals Oy; Metso Outotec Finland Oy | X-ray fluorescence analyzer and a method for performing an x-ray fluorescence analysis |
| 11885755, | May 02 2022 | SIGRAY, INC | X-ray sequential array wavelength dispersive spectrometer |
| 11992350, | Mar 15 2022 | SIGRAY, INC | System and method for compact laminography utilizing microfocus transmission x-ray source and variable magnification x-ray detector |
| 12153001, | Dec 07 2020 | Sigray, Inc. | High throughput 3D x-ray imaging system using a transmission x-ray source |
| 12181423, | Sep 07 2023 | SIGRAY, INC | Secondary image removal using high resolution x-ray transmission sources |
| 7062015, | Oct 28 2002 | United Kingdom Research and Innovation | Method and apparatus for obtaining simultaneously absorption and refraction images by use of a monochromator with integrated radiation detector |
| 7366374, | May 22 2007 | General Electric Company | Multilayer optic device and an imaging system and method using same |
| 7412131, | Jan 02 2007 | General Electric Company | Multilayer optic device and system and method for making same |
| 7508911, | Sep 19 2007 | General Electric Company | X-ray imaging system and methods of using and forming an array of optic devices therein |
| 7583789, | Aug 01 2005 | The Research Foundation of State University of New York; X-Ray Optical Systems, Inc. | X-ray imaging systems employing point-focusing, curved monochromating optics |
| 7742566, | Dec 07 2007 | General Electric Company | Multi-energy imaging system and method using optic devices |
| 7801272, | Sep 28 2007 | Rigaku Corporation | X-ray diffraction apparatus and X-ray diffraction method |
| 7933383, | Apr 11 2008 | RIGAKU INNOVATIVE TECHNOLOGIES, INC | X-ray generator with polycapillary optic |
| 7991116, | Aug 04 2005 | X-RAY OPTICAL SYSTEMS, INC | Monochromatic x-ray micro beam for trace element mapping |
| 8208602, | Feb 22 2010 | General Electric Company | High flux photon beams using optic devices |
| 8311184, | Aug 30 2010 | General Electric Company | Fan-shaped X-ray beam imaging systems employing graded multilayer optic devices |
| 8488743, | Apr 11 2008 | Rigaku Innovative Technologies, Inc. | Nanotube based device for guiding X-ray photons and neutrons |
| 8744048, | Dec 28 2010 | BAKER HUGHES, A GE COMPANY, LLC | Integrated X-ray source having a multilayer total internal reflection optic device |
| 8761346, | Jul 29 2011 | General Electric Company | Multilayer total internal reflection optic devices and methods of making and using the same |
| 9335280, | Oct 06 2011 | X-RAY OPTICAL SYSTEMS, INC | Mobile transport and shielding apparatus for removable x-ray analyzer |
| 9410906, | Mar 27 2013 | HITACHI HIGH-TECH SCIENCE CORPORATION | X-ray fluorescence spectrometer comprising a temperature sensor, two external-air fans, and a circulation fan |
| 9448191, | Dec 28 2011 | X RAY TECHNOLOGY CO , LTD | X-ray fluorescence spectrometer and X-ray fluorescence analyzer |
| 9449780, | Feb 28 2012 | X-RAY OPTICAL SYSTEMS, INC | X-ray analyzer having multiple excitation energy bands produced using multi-material x-ray tube anodes and monochromating optics |
| 9633753, | Oct 06 2011 | X-Ray Optical Systems, Inc. | Mobile transport and shielding apparatus for removable x-ray analyzer |
| 9883793, | Aug 23 2013 | The Schepens Eye Research Institute, Inc. | Spatial modeling of visual fields |
| RE48612, | Oct 31 2013 | Sigray, Inc. | X-ray interferometric imaging system |
| Patent | Priority | Assignee | Title |
| 4562585, | Jun 30 1981 | Siemens Aktiengesellschaft | Sequential x-ray crystal spectrometer |
| 4599741, | Nov 04 1983 | USC--Dept. of Materials Science | System for local X-ray excitation by monochromatic X-rays |
| 5175755, | Apr 01 1991 | X-RAY OPTICAL SYSTEMS, INC , R D 2, BOX 372, VOORHEESVILLE, NY 12186 A CORP OF NY | Use of a Kumakhov lens for X-ray lithography |
| 5192869, | Oct 31 1990 | X-RAY OPTICAL SYSTEMS, INC , R D 2, BOX 372, VOORHEESVILLE, COUNTY OF ALBANY, NY 12186 A CORP OF NY | Device for controlling beams of particles, X-ray and gamma quanta |
| 5406609, | Apr 09 1992 | Rigaku Corporation | X-ray analysis apparatus |
| 5497008, | Oct 13 1990 | X-Ray Optical Systems, Inc. | Use of a Kumakhov lens in analytic instruments |
| 5570408, | Feb 28 1995 | X-RAY OPTICAL SYSTEMS, INC | High intensity, small diameter x-ray beam, capillary optic system |
| 5604353, | Jun 12 1995 | X-Ray Optical Systems, Inc.; X-RAY OPTICAL SYSTEMS, INC | Multiple-channel, total-reflection optic with controllable divergence |
| 5745547, | Aug 02 1996 | X-Ray Optical Systems, Inc.; X-RAY OPTICAL SYSTEMS, INC | Multiple channel optic |
| 5892809, | Sep 08 1998 | Simplified system for local excitation by monochromatic x-rays | |
| 5982847, | Oct 28 1996 | X-RAY OPTICAL SYSTEMS, INC | Compact X-ray fluorescence spectrometer for real-time wear metal analysis of lubrucating oils |
| 6285506, | Jan 21 1999 | X-Ray Optical Systems, Inc.; X-RAY OPTICAL SYSTEMS, INC | Curved optical device and method of fabrication |
| 6317483, | Nov 29 1999 | X-Ray Optical Systems, Inc.; X-RAY OPTICAL SYSTEMS, INC | Doubly curved optical device with graded atomic planes |
| 6697454, | Jun 29 2000 | X-RAY OPTICAL SYSTEMS, INC | X-ray analytical techniques applied to combinatorial library screening |
| EP339713, | |||
| EP724150, | |||
| WO139211, | |||
| WO225258, |
| Executed on | Assignor | Assignee | Conveyance | Frame | Reel | Doc |
| Dec 14 2003 | CHEN, ZEWU | X-RAY OPTICAL SYSTEMS, INC | ASSIGNMENT OF ASSIGNORS INTEREST SEE DOCUMENT FOR DETAILS | 014838 | /0956 | |
| Dec 19 2003 | X-Ray Optical Systems, Inc. | (assignment on the face of the patent) | / | |||
| Dec 19 2003 | GIBSON, DAVID M | X-RAY OPTICAL SYSTEMS, INC | ASSIGNMENT OF ASSIGNORS INTEREST SEE DOCUMENT FOR DETAILS | 014838 | /0956 |
| Date | Maintenance Fee Events |
| Feb 04 2009 | M2551: Payment of Maintenance Fee, 4th Yr, Small Entity. |
| Feb 22 2013 | M1552: Payment of Maintenance Fee, 8th Year, Large Entity. |
| Feb 26 2013 | STOL: Pat Hldr no Longer Claims Small Ent Stat |
| Feb 23 2017 | M1553: Payment of Maintenance Fee, 12th Year, Large Entity. |
| Date | Maintenance Schedule |
| Aug 23 2008 | 4 years fee payment window open |
| Feb 23 2009 | 6 months grace period start (w surcharge) |
| Aug 23 2009 | patent expiry (for year 4) |
| Aug 23 2011 | 2 years to revive unintentionally abandoned end. (for year 4) |
| Aug 23 2012 | 8 years fee payment window open |
| Feb 23 2013 | 6 months grace period start (w surcharge) |
| Aug 23 2013 | patent expiry (for year 8) |
| Aug 23 2015 | 2 years to revive unintentionally abandoned end. (for year 8) |
| Aug 23 2016 | 12 years fee payment window open |
| Feb 23 2017 | 6 months grace period start (w surcharge) |
| Aug 23 2017 | patent expiry (for year 12) |
| Aug 23 2019 | 2 years to revive unintentionally abandoned end. (for year 12) |